Scintillator panel and radiation image sensor

ABSTRACT

An Ag film as a light-reflecting film is formed on one surface of an a-C substrate of a scintillator panel. The entire surface of the Ag film is covered with an SiN film for protecting the Ag film. A scintillator having a columnar structure, which converts an incident radiation into visible light, is formed on the surface of the SiN film. The scintillator is covered with a polyparaxylylene film together with the substrate.

RELATED APPLICATIONS

This is a Continuation-In-Part application of International PatentApplication serial No. 09/971,943 filed on Oct. 9, 2001 now pending.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a scintillator panel and radiationimage sensor which are used for medical X-ray photography or the like.

2. Related Background Art

While X-ray sensitive films have conventionally been used in medical andindustrial X-ray photography, radiation imaging systems using radiationdetectors have been coming into widespread use from the viewpoint ofconvenience and storability of photographed results. In such a radiationimaging system, pixel data caused by two-dimensional radiation areacquired as an electric signal by a radiation detector, and this signalis processed by a processing unit, so as to be displayed on a monitor.

SUMMARY OF THE INVENTION

Conventionally known as a typical radiation detector is one having astructure in which a scintillator panel comprising a scintillator formedon a substrate made of aluminum, glass, fused silica, or the like and animaging device are cemented together. In this radiation detector, theradiation entering from the substrate side is converted by thescintillator into visible light, which is then detected by the imagingdevice (see JP7-21560A).

Meanwhile, though it is necessary for the scintillator panel to have asufficiently high optical output in order to attain clear images in aradiation detector, the optical output has not been sufficient in theabove-mentioned radiation detector.

It is an object of the present invention to provide a scintillator panelhaving an enhanced optical output, and a radiation image sensor using ascintillator panel having an enhanced optical output.

A scintillator panel according to the present invention comprises (1) aradiation-transmitting substrate, (2) a light reflective metal thin filmdisposed on the substrate, (3) a protective film covering an entiresurface of the reflective metal thin film, and (4) a scintillatordeposited on the protective film. And the protective film has a functionto protect the reflective metal thin film against the scintillator.

According to the scintillator panel of the present invention, since theentire surface of the reflective metal thin film is covered with theprotective film, any decomposition of this thin film based on watercontained in the scintillator in a small amount can be prevented, andany degradation in function of the reflective metal thin film as areflecting film can be prevented. Hence, an increased optical output ofthe scintillator panel can be maintained.

Another scintillator panel of the present invention comprises (1) aradiation-transmitting substrate, (2) a reflective metal thin filmdisposed on the substrate, (3) a protective film disposed on thereflective metal thin film, and (4) a scintillator deposited on theprotective film at a position except an edge portion thereof. Thereflective metal thin film transmits radiation and reflects lightirradiated from the scintillator, and has a function to protect thereflective metal thin film against the scintillator.

According to this scintillator panel, since the scintillator andreflective metal thin film are separated, any decomposition of this filmbased on water contained in the scintillator in a small amount can beprevented, and any degradation in function of the reflective metal thinfilm as a reflecting film can be prevented. Hence, an increased opticaloutput of the scintillator panel can be maintained.

The reflective film may be directly or indirectly disposed on thesubstrate. And the reflective film may be substantially made of amaterial containing a substance selected from the group consisting ofAl, Ag, Cr, Cu, Ni, Ti, Mg, Rh, Pt, and Au.

The protective film may be an inorganic film like a metal oxide film oran organic film like polyimide. The inorganic film may be substantiallymade of a material containing a substance selected for the groupconsisting of LiF, MgF₂, SiO₂, TiO₂, Al₂O₃, MgO, SiN. Or the metal oxidefilm may be an oxidized material of the reflective metal thin film.

The protective film preferably comprises an inorganic film such as SiNand an organic film such as polyimide.

The scintillator may be covered with an organic film. According to thisconfiguration, the water-vapor resistance of the scintillator can beimproved.

Preferably, the organic film further covers at least an outer peripheryof said protective film. According to this configuration, the organicfilm covers over the scintillator and the outer periphery of saidprotective film and reaches to the surface of the substrate around theprotective film. Whereby the water-vapor resistance of the scintillatorcan be further improved as compared to a structure in which only thescintillator is covered with an organic film. And the scintillatingmaterial depositing outside the scintillator layer is prevented tocontact with the reflective metal thin film.

If this organic film further covers an entire surface of the substratethen it is preferable to further improve the water-vapor resistance ascompared to a structure in which only the scintillator and at least partof the substrate surface are covered with an organic film.

A radiation image sensor according to the present invention ischaracterized in that an image sensing element is arranged to face thescintillator of the scintillator panel. According to the radiation imagesensor of the present invention, since the scintillator panel canmaintain an increased optical output, the output of the radiation imagesensor can be maintained.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of a scintillator panel according to thefirst embodiment, and

FIG. 2 is a sectional view of a radiation image sensor according to thefirst embodiment;

FIG. 3 is a sectional view of a scintillator panel according to thesecond embodiment;

FIG. 4 is a sectional view of a scintillator panel according to thethird embodiment, and FIG. 5 is a sectional view of a modification ofthis embodiment;

FIG. 6 is a sectional view of a scintillator panel according to thefourth embodiment;

FIG. 7 is a sectional view of a modification to the scintillator panelaccording to the fourth embodiment, and

FIGS. 8 and 9 are sectional views of modifications of this embodiment;

FIG. 10 is a sectional view of a scintillator panel according to thefifth embodiment;

FIG. 11 is a sectional view of a radiation image sensor according to thefifth embodiment;

FIG. 12 is a sectional view of a scintillator panel according to thesixth embodiment, and

FIG. 13 is a sectional view of a modification of this embodiment;

FIG. 14 is a sectional view of a seventh embodiment of the scintillatorpanel according to the present invention, and

FIG. 15 is a sectional view of a seventh embodiment of the radiationimage sensor according to the present invention, which is used in thisscintillator panel;

FIG. 16 is a sectional view of an eighth embodiment of the scintillatorpanel according to the present invention, and

FIG. 17 is a sectional view of a ninth embodiment of the scintillatorpanel according to the present invention;

FIG. 18 is a sectional constitutional diagram showing a tenth embodimentof the scintillator panel according to the present invention,

FIGS. 19A through 19D are views showing the making process thereof, and

FIG. 20 is a detailed explanatory view of the scintillator depositionprocess;

FIG. 21 is a sectional constitutional diagram showing an eleventhembodiment of the scintillator panel according to the present invention;

FIGS. 22 and 23 are sectional constitutional diagrams showing a twelfthembodiment of the scintillator panel according to the present inventionand an example of modification thereof;

FIGS. 24 and 25 are sectional constitutional diagrams showing athirteenth embodiment of the scintillator panel according to the presentinvention and an example of modification thereof;

FIGS. 26A through 26C are explanatory views of the making process of thescintillator panel of FIG. 24;

FIGS. 27A through 27D are sectional constitutional diagrams showing afourteenth embodiment of the scintillator panel according to the presentinvention and an example of modification thereof;

FIGS. 28A through 28C are explanatory views of the making process of thescintillator panel of FIG. 27A;

FIG. 29 is a sectional constitutional diagram showing a fifteenthembodiment of the scintillator panel according to the present invention,and

FIG. 30 is a view showing an example of modification thereof;

FIGS. 31A through 31E are views showing the making process of thescintillator panel of FIG. 29;

FIGS. 32 and 33 are sectional constitutional views showing sixteenth andseventeenth embodiments of the scintillator panel according to thepresent invention;

FIGS. 34A through 34E are explanatory views of the making process of thescintillator panel of FIG. 33; and

FIGS. 35 through 38 are a front view, a rear view, and sectional viewsalong the XXXVII-XXXVII line and the XXXVIII-XXXVIII line of aneighteenth embodiment of the scintillator panel according to the presentinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

We will describe some preferred embodiments of the present inventionhereinafter. To facilitate the comprehension of the explanation, thesame reference numerals denote the same parts, where possible,throughout the drawings, and a repeated explanation will be omitted.

The first embodiment of the present invention will be described belowwith reference to FIGS. 1 and 2. FIG. 1 is a sectional view of ascintillator panel 1, and FIG. 2 is a sectional view of a radiationimage sensor 2.

As shown in FIG. 1, an Ag film 12 as a light-reflecting film (reflectivemetal thin film) is disposed on one surface of an amorphous carbon (a-C)(glassy carbon or glass-like carbon) substrate 10 of the scintillatorpanel 1. The surface of the Ag film 12 is covered with an SiN film 14for protecting the Ag film 12. A scintillator 16 with a columnarstructure, which converts incident radiation into visible light, is madeon the surface of the SiN film 14. Tl-doped CsI is used as thescintillator 16. This scintillator 16 is covered with a polyparaxylylenefilm 18 together with the substrate 10.

The radiation image sensor 2 has a structure in which an image sensingelement 20 is bonded to the distal end portion side of the scintillator16 of the scintillator panel 1, as shown in FIG. 2.

The making process of the scintillator panel 1 will be described. First,an Ag film 12 as a light-reflecting film is formed to a thickness of 150nm on one surface of a rectangular or circular a-C substrate 10(thickness: 1 mm) by vacuum deposition. An SiN film 14 is formed to athickness of 200 nm on the Ag film 12 by plasma CVD to cover the entiresurface of the Ag film 12.

A columnar crystal of Tl-doped CsI is grown (deposited) on the surfaceof the SiN film 14 by deposition, thereby forming a scintillator 16having a thickness of 250 μm. CsI that forms the scintillator 16 hashigh hygroscopicity, and if the scintillator is kept exposed, it absorbsvapor in air and deliquesces. To prevent this deliquescence, apolyparaxylylene film 18 is formed by CVD. That is, the substrate 10with the scintillator 16 formed is placed in a CVD apparatus, and apolyparaxylylene film 18 is deposited to a thickness of 10 m. With theabove process, the polyparaxylylene film 18 is formed on the entiresurfaces of the scintillator 16 and substrate 10 (the entire substratesurface that is exposed without any scintillator or the like).

The radiation image sensor 2 is manufactured by bonding thelight-receiving portion of the image sensing element (CCD) 20 to thedistal end portion side of the scintillator 16 of the completedscintillator panel 1 (FIG. 2).

According to the radiation image sensor 2 of this embodiment, radiationincident from the substrate 10 side is converted into light by thescintillator 16 and detected by the image sensing element 20. Since thescintillator panel 1 of the radiation image sensor 2 has the Ag film 12as a reflective metal thin film, the light incident on thelight-receiving portion of the image sensing element 20 can beincreased, and a clear image can be detected by the radiation imagesensor 2. In addition, since the Ag film 12 is wholly covered with theSiN film 14 that functions as a protective film for the Ag film 12, thefunction for a reflecting film of the Ag film 12 can be prevented frombeing damaged by decomposition due to corrosion or the like.Furthermore, when the scintillator 16 is deposited the CsI deposits notonly on the region on the SiN film 14 but also deposits outside of theSiN film 14. According to the present invention, the outer periphery ofthe SiN film 14 is covered over the polyparaxylylene film 18, the CsIwhich deposits outside of the SiN film 14 cannot intrude into the SiNfilm 14 and cannot contact with Ag film 12. So the Ag film 12 iseffectually protected against the CsI.

The second embodiment of the present invention will be described next.In the second embodiment to be described below, the same referencenumerals as in the scintillator panel 1 and radiation image sensor 2 ofthe first embodiment denote the same components in the secondembodiment.

FIG. 3 is a sectional view of a scintillator panel 3. As shown in FIG.3, an Al film 13 serving as a reflecting film is formed on one surfaceof an a-C substrate 10 of the scintillator panel 3. The surface of theAl film 13 is covered with a polyimide film 22 for protecting the Alfilm 13. A scintillator 16 with a columnar structure, which convertsincident radiation into visible light, is formed on the surface of thepolyimide film 22. Tl-doped CsI is used as the scintillator 16. Thisscintillator 16 is covered with a polyparaxylylene film 18 together withthe substrate 10.

A radiation image sensor is constructed by bonding an image sensingelement to the distal end portion side of the scintillator 16 of thescintillator panel 3.

The making process of the scintillator panel 3 will be described. First,an Al film 13 as a light-reflecting film is formed to a thickness of 150nm on one surface of a rectangular or circular a-C substrate 10(thickness: 1 mm) by vacuum deposition. A polyimide film 22 is formed toa thickness of 1,000 nm on the Al film 13 by a spin coat process tocover the entire surface of the Al film 13.

A columnar crystal of Tl-doped CsI is grown on the surface of thepolyimide film 22 by deposition, thereby forming a scintillator 16having a thickness of 250 μm. CsI that forms the scintillator 16 hashigh hygroscopicity, and if the scintillator is kept exposed, it absorbsvapor in air and deliquesces. To prevent this deliquescence, thepolyparaxylylene film 18 is formed by CVD. That is, the polyparaxylylenefilm 18 is formed on the entire surfaces of the scintillator 16 andsubstrate 10.

The radiation image sensor is manufactured by bonding thelight-receiving portion of an image sensing element (CCD) 20 to thedistal end portion side of the scintillator 16 of the completedscintillator panel 3.

According to the radiation image sensor using the scintillator panel 3of this embodiment, radiation incident from the substrate 10 side isconverted into light by the scintillator 16 and detected by the imagesensing element 20. Since the scintillator panel 3 of the radiationimage sensor has the Al film 13 as a reflective metal thin film, thelight incident on the light-receiving portion of the image sensingelement can be increased, and a clear image can be detected by theradiation image sensor. In addition, since the Al film 13 is whollycovered with the polyimide film 22 that functions as a protective filmfor the Al film 13, the Al film 13 as a reflecting film can be preventedfrom being damaged in function by a decomposition due to corrosion orthe like.

The third embodiment of the present invention will be described next. Inthe third embodiment to be described below, the same reference numeralsas in the scintillator panel 1 and radiation image sensor 2 of the firstembodiment denote the same components in the third embodiment.

FIG. 4 is a sectional view of a scintillator panel 4. As shown in FIG.4, an Ag film 12 as a light-reflecting film is formed on one surface ofan a-C substrate 10 of the scintillator panel 4. An SiN film 14 forprotecting the Ag film 12 is formed on the entire surface of the Ag film12. A scintillator 16 with a columnar structure, which converts anincident radiation into visible light, is formed on the surface of theSiN film 14.

The scintillator 16 is formed at a position except the edge portion onthe SiN film 14 so that the scintillator 16 located on the outer side isseparated from the edge portion of the Ag film 12. Tl-doped CsI is usedas the scintillator 16. This scintillator 16 is covered with apolyparaxylylene film 18 together with the substrate 10.

A radiation image sensor is constructed by bonding an image sensingelement to the distal end portion side of the scintillator 16 of thescintillator panel 4.

According to the radiation image sensor using the scintillator panel 4of this embodiment, radiation incident from the substrate 10 side isconverted into light by the scintillator 16 and detected by an imagesensing element 20. Since the scintillator panel 4 of the radiationimage sensor has the Ag film 12 as a reflective metal thin film, thelight incident on the light-receiving portion of the image sensingelement 20 can be increased, and a clear image can be detected by theradiation image sensor. In addition, since the edge portion of the Agfilm 12 is separated from the scintillator 16, the Ag film 12 as areflecting film can be prevented from being damaged in function by adecomposition due to corrosion or the like.

In the scintillator panel 4 according to the third embodiment, the SiNfilm 14 is formed on the entire surface of the Ag film 12. However, asin a scintillator panel 5 shown in FIG. 5, the SiN film 14 may be formedat a position except the edge portion of the Ag film 12, and thescintillator 16 may be formed at a position except the edge portion ofthe SiN film 14. Even in this case, since the edge portion of the Agfilm 12 is separated from the scintillator 16, the Ag film 12 as areflecting film can be prevented from being damaged in function by adecomposition due to corrosion or the like.

The fourth embodiment of the present invention will be described next.In the fourth embodiment to be described below, the same referencenumerals as in the scintillator panel 1 and radiation image sensor 2 ofthe first embodiment denote the same components in the fourthembodiment.

FIG. 6 is a sectional view of a scintillator panel 6. As shown in FIG.6, an Al film 24 made of an Al film 24 a and Al₂O₃ film (oxide film) 24b is formed on one surface of an a-C substrate 10 of the scintillatorpanel 6. A scintillator 16 with a columnar structure, which converts anincident radiation into visible light, is formed on the Al₂O₃ film 24 bon the surface of the Al film 24. Tl-doped CsI is used as thescintillator 16. This scintillator 16 is covered with a polyparaxylylenefilm 18 together with the substrate 10.

A radiation image sensor is constructed by bonding an image sensingelement to the distal end portion side of the scintillator 16 of thescintillator panel 6.

The making process of the scintillator panel 6 will be described. First,an Al film 24 as a light-reflecting film is formed to a thickness of 150nm on one surface of a rectangular or circular a-C substrate 10(thickness: 1 mm) by vacuum deposition. Subsequently, Al is evaporatedwhile supplying oxygen gas, thereby forming an Al₂O₃ film 24 b having athickness of 30 nm on the entire surface of the Al film 24 a.

A columnar crystal of Tl-doped CsI is grown on the surface of the Al₂O₃film 24 b by deposition, thereby forming a scintillator 16 having athickness of 250 μm. CsI that forms the scintillator 16 has highhygroscopicity, and if the scintillator is kept exposed, it absorbsvapor in air and deliquesces. To prevent this deliquescence, apolyparaxylylene film 18 is formed by CVD. That is, the polyparaxylylenefilm 18 is formed on the entire surfaces of the scintillator 16 andsubstrate 10.

A radiation image sensor is constructed by bonding an image sensingelement to the distal end portion side of the scintillator 16 of thescintillator panel 6.

According to the radiation image sensor using the scintillator panel 6of this embodiment, radiation incident from the substrate 10 side isconverted into light by the scintillator 16 and detected by an imagesensing element 20. Since the scintillator panel 6 of the radiationimage sensor has the Al film 24 a as a reflective metal thin film, thelight incident on the light-receiving portion of the image sensingelement 20 can be increased, and a clear image can be detected by theradiation image sensor.

In addition, since the Al film 24 a is wholly covered with the Al₂O₃film 24 b as a protective film for the Al film 24 a, the Al film 24 a asa reflecting film can be prevented from being damaged in function by adecomposition due to corrosion or the like. In addition, since the edgeportion of the Ag film 12 is separated from the scintillator 16, the Agfilm 12 as a reflecting film can be prevented from being damaged infunction by a decomposition due to corrosion or the like. In thescintillator panel 6 according to the fourth embodiment, the Al₂O₃ film24 b is formed on the entire surface of the Al film 24 a. However, as ina scintillator panel 7 shown in FIG. 7, the Al₂O₃ film 24 b may beformed at a position except the edge portion of the Al film 24 a. Evenin this case, since the edge portion of the Al film 24 is separated fromthe scintillator 16, the Al film 24 a as a reflecting film can beprevented from being damaged in function by a decomposition due tocorrosion or the like.

In the above-described embodiments, an a-C substrate is used. However,since the substrate only need to pass radiation, a graphite substrate,Al substrate, Be substrate, or glass substrate may be used.

In the above-described embodiments, when an Al oxide film on thesubstrate is used as a protective film, a polyimide film as a protectivefilm is also preferably formed on the oxide film. In this case, the Alfilm can be completely protected by the oxide film and polyimide film.

In the above-described embodiments, an SiN film or polyimide film isused as a protective film. However, the present invention is not limitedto this. A film made of a material containing a substance selected fromthe group consisting of transparent inorganic films such as LiF, MgF₂,SiO₂, Al₂O₃, TiO₂, MgO, and SiN and a transparent organic film such aspolyimide may be used. Alternatively, a protective film formed frominorganic and organic films may be used, as shown in FIG. 8. That is, ina scintillator panel shown in FIG. 8, an Ag film 12 as alight-reflecting film is formed on one surface of an a-C substrate 10.The surface of the Ag film 12 is covered with the SiN film (inorganicfilm) 14 for protecting the Ag film 12, and the surface of the SiN film14 is covered with a polyimide film (organic film) 22. A scintillator 16having a columnar structure is formed on the surface of the polyimidefilm 22. The scintillator 16 is covered with a polyparaxylylene film 18together with the substrate 10. When a protective film formed frominorganic and organic films is used, as in the scintillator panel shownin FIG. 8, the effect for protecting the light-reflecting film can befurther improved.

In the above-described embodiments, an Ag film or Al film is used as areflective metal thin film. However, a film made of a materialcontaining a substance selected from the group consisting of Al, Ag, Cr,Cu, Ni, Ti, Mg, Rh, Pt, and Au may be used. In addition, two or morereflective metal thin films may be formed by forming, e.g., an Au filmon a Cr film.

In the above-described embodiments, when a film made of a materialcontaining a substance selected from the group consisting of Al, Ag, Cr,Cu, Ni, Ti, Mg, Rh, and Pt is used as a reflective metal thin film, anoxide film thereof can be used as a protective film.

In the above-described embodiments, the entire surfaces of thescintillator 16 and substrate (the surface with the scintillator formedand a surface on the opposite side, i.e., the radiation incidentsurface) are covered with the polyparaxylylene film 18, thereby makingthe scintillator completely resistant against water vapor. When theentire surface of the scintillator 16 and at least part of the surfaceof the substrate 10 are covered with the polyparaxylylene film 18, asshown in FIG. 9, the water-vapor resistance of the scintillator can bemade higher than in a case wherein only the scintillator is covered.

The fifth embodiment of the present invention will be described next. Inthe fifth embodiment to be described below, the same reference numeralsas in the scintillator panels 1 and 3 and the radiation image sensor 2of the first and second embodiments denote the same components in thefifth embodiment.

As shown in FIG. 10, a scintillator panel 8 has a glass substrate 26having a flat shape. An Al film 13 as a reflecting film is formed to athickness of 100 nm on one surface of the substrate by vacuumdeposition. A 250-μm thick scintillator 16 with a columnar structure,which converts an incident radiation into visible light, is formed onthe surface of the Al film 13. Tl-doped CsI grown by deposition is usedfor the scintillator 16.

The entire surface of the scintillator 16 is covered with a 10-μm thickpolyparaxylylene film (transparent organic film) 18 formed by CVD,together with the substrate 26.

A radiation image sensor has a structure in which an image sensingelement 20 is bonded to the distal end portion side of the scintillator16 of the scintillator panel 8, as shown in FIG. 11.

According to the radiation image sensor of this embodiment, radiationincident from the substrate 26 side is converted into light by thescintillator 16 and detected by the image sensing element 20. Since thescintillator panel 8 of the radiation image sensor has the Al film 13 asa reflecting film, the light incident on the light-receiving portion ofthe image sensing element 20 can be increased, and a clear image can bedetected by the radiation image sensor.

The substrate used for the scintillator panel 8 is preferably made thinto increase the radiation transmittance. When a glass substrate is used,a given rigidity can be ensured as compared to an Al substrate or a-Csubstrate even when the panel size is increased as in a scintillatorpanel used for a radiation image sensor for chest. For this reason, anydeflection of the substrate can be prevented in forming a scintillatoron the glass substrate. Hence, the scintillator can easily be formed onthe substrate, and the quality of the formed scintillator can bemaintained. As a type of glass to be used for the glass substrate ofthis embodiment, Pyrex glass is preferably used because of its cost anda small content of radiation absorbing component.

The sixth embodiment of the present invention will be described next. Inthe sixth embodiment to be described below, the same reference numeralsas in the scintillator panel 5 and radiation image sensor of the fifthembodiment denote the same components in the sixth embodiment.

As shown in FIG. 12, a scintillator panel 9 has a glass substrate 26having a flat shape. A Cr film 28 as a reflecting film is formed to athickness of 100 nm on one surface of the substrate by vacuumdeposition. An Au film 30 is formed on the surface of the Cr film 28,and a 250-μm thick scintillator 16 with a columnar structure is formedon the surface of the Au film 30. Tl-doped CsI grown by deposition isused as the scintillator 16.

The entire surface of the scintillator 16 is covered with a 10-μm thickpolyparaxylylene film (transparent organic film) 18 formed by CVD,together with the substrate 26. A radiation image sensor has a structurein which an image sensing element 20 is bonded to the distal end portionside of the scintillator 16 of the scintillator panel 9.

Since the reflecting film of the scintillator panel according to thisembodiment is formed from the Cr film 28 with good adhesion to the glasssubstrate and the Au film 30 with good bonding to Cr, the reflectingfilm can have high stability.

In the above-described embodiments, a film made of a material containinga substance selected from the group consisting of Al, Ag, Cr, Cu, Ni,Ti, Mg, Rh, Pt, and Au may be used as a reflective metal thin film.

Next, the seventh embodiment of the present invention will be described.FIG. 14 is a sectional view of the scintillator panel 1 a of the seventhembodiment, and FIG. 15 is a sectional view of the radiation imagesensor 2 a which is used in the scintillator panel 1 a.

As is illustrated in FIG. 14, a polyimide intermediate film 31 isdisposed on one surface of the amorphous carbon (a-C) (glassy carbon orglass-like carbon) substrate 10 of the scintillator panel 1 a byadhesion, and a metal thin film 12 which functions as a light-reflectingfilm is formed on the surface of this intermediate film 31 by adhesion.This metal thin film is manufactured from Al, for example. The surfaceof this metal thin film 12 is covered by a polyimide protective film 34for protecting the metal thin film 12. As a result, the metal thin film12 is sandwiched between, and thus sealed by, the intermediate film 31and the protective film 34 to which it is adhered. A scintillator 16with a columnar structure, which converts incident radiation intovisible light, is formed on the surface of the protective film 34. Inother words, the structure of the scintillator 16 is such that a largenumber of columnar crystals stand grouped together on the protectivefilm 34. Further, a Tl-doped CsI is used in the scintillator 16. Thisscintillator 16, as well as the substrate 10, is covered with apolyparaxylylene moisture-resistant protective film 18.

As is shown in FIG. 15, the radiation image sensor 2 has a configurationin which the light-receiving surface of an image-sensing element 20 isaffixed to the side of the scintlillator panel 1 a on which thescintillator 16 is formed.

Next, the making process for the scintillator panel la will beexplained. First, polyimide resin is painted onto one surface of therectangular or circular a-C substrate 10 (thickness: 1 mm) at a constantthickness (10 μm) and caused to harden, thereby becoming adhered to thesubstrate 10 and forming the intermediate film 31 with a flat surface.

The metal thin film 12 which functions as a light-reflecting film isformed on the surface of this intermediate film 31 at a thickness of 150nm by vacuum deposition. The polyimide constituting the intermediatefilm 31 has a good affinity with the Al metal thin film 12, and hence,the metal thin film 12 becomes adhered to the intermediate film 31.Since the intermediate film 31 is also adhered to the substrate 10,peeling away of the metal thin film 12 from the substrate 10 can beeffectively prevented.

Subsequently, spin coat processing is applied onto the metal thin film12, thus forming a polyimide protective film 34 at a thickness of 1000nm which covers the entire metal thin film 12. As a result, the metalthin film 12 is sandwiched between the intermediate film 31 and theprotective film 34 so as to be adhered to and sealed by both, and hencecan be effectively protected from damage or peeling in the subsequentmaking process.

Next, a large number of Tl-doped CsI columnar crystals are grown(accumulated) by deposition on the surface of the protective film 34 soas to stand grouped together, thereby forming the scintillator 16 at athickness of 250 μm. The CsI that forms the scintillator 16 has highhygroscopicity, and if left exposed, absorbs vapor in the air anddeliquesces. In order to prevent this, the polyparaxylylenemoisture-resistant protective film 18 is formed by CVD. That is, thesubstrate 10 on which the scintillator 16 is formed is inserted into aCVD device, and the moisture-resistant protective film 18 is formed at athickness of 10 μm. The making method for this moisture-resistantprotective film 18 is described in detail in International PublicationNo. WO99/66351. Thereby, the polyparaxylylene moisture-resistantprotective film 18 is formed on substantially the entire surface of thescintillator 16 and the substrate 10, or in other words, substantiallythe entire surface of the substrate that is exposed and does not have ascintillator or the like formed thereon. According this process theprotective film 18 is not formed at positions corresponding to thesupport protrusions of a target-support element each of which supportsthe substrate during CVD process. The words “substantially the entiresurface” means almost entire surfaces except these portions.

The radiation image sensor 2 a is made by disposing the light-receivingportion of an image sensing element (CCD) 20 to face the distal end sideof the scintillator 16 of the completed scintillator panel 1 a andbonding them (see FIG. 15).

According to the radiation image sensor 2 a of this embodiment,radiation which enters from the substrate 10 side is converted intolight by the scintillator 16 and detected by the image sensing element20. Since the light-reflecting metal thin film 12 is provided in thescintillator panel 1 a comprising the radiation image sensor 2, theamount of light incident on the light-receiving portion of theimage-sensing element 20 can be increased, and the image detected by theradiation image sensor 2 can be made clearer. Further, since the metalthin film 12 is adhered to the polyimide intermediate film 31 and theprotective film 34, and thus sandwiched between the two to seal theentire film, damage to the function of the metal thin film 12 as areflecting film due to deterioration such as corrosion, peeling, orother impairments, can be prevented, and the stability thereof as areflecting film can be improved.

FIG. 16 is a sectional view of an eighth embodiment of the scintillatorpanel in accordance with the present invention. This scintillator panel3 a differs from the first embodiment in that the protective film 34 adoes not cover the entire surface of the metal thin film 12, but rathercovers only the central part of the metal thin film 12. In thisembodiment also, the scintillator 16 is formed only on the surface ofthe protective film 34 a, and thus the metal thin film 12 is completelyprevented from contacting the scintillator 16 by the protective film 34a.

In this embodiment also, at least the scintillator 16 formation part ofthe metal thin film 12 is sandwiched between, and sealed by, theintermediate film 31 and the protective film 34 a, and hence, damage,peeling, deterioration and the like can be effectively prevented, andthe stability of the metal thin film 12 as a reflecting film can beimproved.

FIG. 17 is a sectional view of the ninth embodiment of the scintillatorpanel in accordance with the present invention. This scintillator panel4 a differs from those of the seventh and eighth embodiments,illustrated in FIGS. 14 and 16, in that a polyparaxylylene film which isthe same as the moisture-resistant protective film 18 is used as theintermediate film 31 b and the protective film 34 b. Furthermore, theintermediate film 31 b covers the entire substrate 10, and theprotective film 34 b covers the metal thin film 12 and the exposedintermediate film 31 b on the periphery of the metal thin film 12.

Similarly to the case of the aforementioned moisture-resistantprotective film 18, the intermediate film 31 b and the protective film34 b are formed by CVD, thus forming a satisfactory thin film that isuniform and has no pin holes or the like. As a result the metal thinfilm 12 is sealed, and contact with the outside air and the scintillator16 which is formed on the protective film 34 b is completely prevented,and thereby, reactions of the metal with scintillator components andmoisture can be suppressed. In particular, during the formation of thescintillator 16, the protective film 34 b completely covers thesubstrate 10 and the metal thin film 12, and thus even the effects ofthe scintillator components becoming attached to another location can besuppressed. Furthermore, by interposing the intermediate film 31 b,which is a nonconductor, between the substrate 10 and the metal thinfilm 12, which have conducting properties, electrical contact betweenthe substrate 19 and the metal thin film 12 can be prevented, andelectric corrosion of the metal thin film 12 can be effectivelysuppressed.

Here, an embodiment was explained in which the intermediate film 31 band the protective film 34 b cover the entire substrate 10; however, itis sufficient if the metal thin film 12 is formed on the surface of theintermediate film 31 b, and the intermediate film 31 b may be formed ononly the formation surface side of the scintillator 16 on the substrate.It is also sufficient if the protective film 34 b is formed on at leastthe formation surface part of the scintillator 16, as in the eighthembodiment. However, if a structure such as that of the presentembodiment is employed, wherein the intermediate film 31 b and theprotective film 34 b cover the entire substrate 10, sealing is improved,and the formation of the films by CVD is simple, and therefore thisstructure is preferable.

A tenth embodiment of the scintillator panel in accordance with thepresent invention will now be explained. FIG. 18 is a sectional viewshowing this scintillator panel 1 b. In the scintillator panel 1 b, ametal reflective film 12 is formed on one surface of the radiolucentsubstrate 10 (made of a material in which the main component is glass,amorphous carbon, or another carbon). This metal reflective film 12 iscomprised of a material containing one of Al, Ag, Cr, Cu, Ni, Ti, Mg, orRh. A protective organic film 14 is formed so as to envelop thesubstrate 10 from above the metal reflective film 12. This protectiveorganic film 14 is made, for example, from polyparaxylylene. Ascintillator 16 which converts into visible light incident radiationthat has passed through the substrate 10 is formed on the portion of thesurface where the metal reflective film 12 and the protective organicfilm 14 are laminated. A Tl-doped CsI, for example, is used in thisscintillator 16. The CsI has a configuration in which a large number ofneedle crystals stand grouped together. This scintillator 16, as well asthe substrate 10, is covered by a moisture-proof organic film 18 made ofpolyparaxylylene.

Next, the making process of this scintillator panel 1 b will beexplained with reference to FIGS. 18, 19A through 19D, and 20. First, arectangular or circular substrate 10 (thickness: 1 mm) is prepared (seeFIG. 19A), and the metal reflective film 12 is formed on a surfacethereof at a thickness of 150 nm by vacuum deposition (see FIG. 19B).

Next, the polyparaxylylene protective organic film 14 is formed on themetal reflective film 12 by CVD. In other words, the substrate 10 withthe metal reflective film 12 deposited thereon is inserted into a CVDdevice, whereby the moisture-proof organic film 12 is formed over theentire surface of the substrate 10 at a thickness of 10 μm. As a result,the metal reflective film 12 is covered, and the polyparaxylyleneprotective organic film 14 is formed covering substantially the entiresubstrate 10, from the periphery of the metal reflective film 12 to theside walls and moreover to the rear surface thereof (see FIG. 19C). Thisorganic film making method is described in detail in InternationalPublication No. WO99/66351.

Subsequently, a large number of Tl-doped CsI needle crystals are grown(accumulated) by deposition in a predetermined area on the surface ofthe protective organic film 14 on the metal reflective film 12, and thusthe scintillator 16 is formed at a thickness of 250 μm (see FIGS. 19D,20). At the time of this deposition, the substrate 10 which is coveredby the protective organic film 14 is housed in a cavity portion 200 x ofa deposition holder 200, and only the part of the substrate 10 on whichthe scintillator 16 is to be formed (the aforementioned predeterminedarea) is exposed to the deposition chamber 400 side through an opening201 provided in the deposition holder 200. Thereby, the scintillator 16can be selectively formed in a substantially predetermined area. It isconceivable that the scintillator components that pass through theopening 201, that is, one part of the CsI component, pass through thegap between the protective organic film 14 and the floor surface of thecavity portion 200 x, thus becoming attached to the protective organicfilm 14 on the side wall of the substrate 10; however, these componentsalmost never reach the protective organic film 14 on the rear surfaceside of the substrate 10. If a cover plate 300 is disposed on the rearsurface of the substrate 10 to cover the rear surface of the substrate10, attachment to this rear surface can be completely prevented, and itis therefore preferable to provide this cover plate 300.

The CsI which forms this scintillator 16 has high hygroscopicity, and ifleft exposed, absorbs vapor in the air and deliquesces. In order toprevent this, the scintillator 16 is further covered by apolyparaxylylene moisture-proof organic film 18 (thickness: 10 μm),thereby completing the scintillator panel 1 b illustrated in FIG. 18.This moisture-proof organic film 18 maybe formed using the same makingmethod as for the protective organic film 14.

In the scintillator panel 1 b of this embodiment, the protective organicfilm 14 covering the metal reflective film 12 does not only cover themetal reflective film 12, but also covers the substrate 10 from theperiphery of the metal reflective film 12 to the side wall parts andfurthermore to the rear surface thereof. Therefore, even whenscintillator components which have passed through the opening 201 becomeattached to the protective organic film 14, these scintillatorcomponents can be securely prevented from penetrateing between theprotective organic film 14 and the substrate 10 to reach the metalreflective film 12. Thus, deterioration of the metal reflective film 12can be suppressed, and the durability thereof can be improved. Moreover,peeling of the protective organic film 14 can be securely prevented.

In this scintillator panel 1 b, as illustrated in FIG. 18, thescintillator 16 is disposed facing the opposite side to the radiationentrance side, and the image-sensing element, television camera and soon are disposed and used on the scintillator 16 side. Radiation entersthe scintillator panel 1 b from the direction of arrow A, penetrates themoisture-resistant protective film 14, protective organic film 14,substrate 10, metal reflective film 12, and protective organic film 14in succession, and reaches the scintillator 16. Here, the radiation isabsorbed by the scintillator 16 and emitted as visible light. Of theemitted visible light, the light directed toward the substrate 10 sidepasses through the transparent protective organic film 14, and isthereafter reflected by the metal reflective film 12 to return to thescintillator 16 side. As a result, the bulk of the light emitted fromthe scintillator 16 passes through the moisture-resistant protectivefilm 14 and is radiated in the direction of arrow B. In theimage-sensing element or television camera (not shown), this opticalimage is captured, whereby an image signal corresponding to aradiographic image can be obtained.

This protective organic film 14 does not have to cover the entire rearsurface of the substrate 10; it is sufficient if the protective organicfilm 14 covers the side wall part and extends to the edges of the rearsurface side, as does the protective organic film 14 a in the eleventhembodiment, shown in FIG. 21. In this case, even if scintillatorcomponents become attached to the rear surface part of the substrate 10which is exposed during the deposition of the scintillator 16, theprotective organic film 14 a becomes adhered to the side wall of thesubstrate 10 such that penetrating between the protective organic film14 a and the substrate 10 becomes difficult. Furthermore, thescintillator components are covered and encapsulated by themoisture-resistant organic film 14 in a subsequent procedure, and thusundergo no further movement, meaning that deterioration of the metalreflective film 12 can be suppressed.

FIGS. 22 and 23 are sectional views showing the twelfth embodiment ofthe scintillator panel according to the present invention and an exampleof a modification thereof respectively. These embodiments differ fromthe tenth and eleventh embodiments in that a film made of polyimide isused as the protective organic films 14 b and 14 b′.

These polyimide protective organic films 14 b and 14 b′ can be madefollowing the making process of the metal reflective film 12, shown inFIG. 19B, by applying polyimide resin over the metal reflective film 12down to the side walls of the substrate 10 at a constant thickness (10μm) and causing this resin to harden.

Here also, when a protective organic film is formed using polyimideresin, the protective organic film 14 b must be formed up to the edgesof the side walls and the rear surface of the substrate 10, as is shownin FIG. 22, and it is preferable that the protective organic film 14 b′be formed over the rear surface edges, as is shown in FIG. 23.

FIGS. 24 and 25 are sectional views showing the thirteenth embodiment ofthe scintillator panel according to the present invention and an exampleof a modification thereof. These embodiments are similar to the twelfthembodiment in that a polyimide protective organic film 14 c is used, butdiffer in that the protective organic film 14 c comprises two parts: asecond protective organic film 141 in the form of a picture frame casingwhich principally covers the side walls of the substrate 10; and a firstprotective organic film 140 in a substantially planar form, whichprincipally covers the metal reflective film 12.

Here, the second protective organic film 141 is formed over the sidewalls of the substrate 10 from the peripheral edges of the metalreflective film 12. As is shown in FIG. 24, it is preferable that thesecond protective organic film 141 extend to the rear surface of thesubstrate 10; however, it is acceptable for this film to extend to theedges of the rear surface of the substrate 10, as is shown in FIG. 25.

Next, the making method of this scintillator panel 1 e will beexplained. This method is identical to the making process for thescintillator panel 1 b illustrated in FIGS. 19A and 19B up to themanufacture of the metal reflective film 12. Thereafter, polyimide resinis painted onto the side walls of the substrate 10 and the proximalsubstrate surfaces up to the peripheral edges of the metal reflectivefilm 12, and then this resin is hardened, thus forming the secondprotective organic film 141 in a frame shape (see FIG. 26A). The secondprotective organic film 141 may also be formed by affixing resin in theform of a tape or a film rather than by painting.

Next, polyimide resin is painted onto the second protective organic film141 over the metal reflective film 12 and around the periphery thereof,and then caused to harden, thus forming the first protective organicfilm 140 in planar form to cover the metal reflective film 12 (see FIG.26B). Thereafter, similarly to the process in FIG. 19D, a large numberof Tl-doped CsI needle crystals are grown by deposition in apredetermined area on the surface of the protective organic film 14 c(actually, the first protective organic film 140) over the metalreflective film 12, and thus the scintillator 16 is formed (see FIG. 26c). To complete the scintillator panel 1 e illustrated in FIG. 24, thescintillator 16 is covered with a moisture-proof organic film 18 made ofpolyparaxylylene.

In forming the protective organic film 14 c in two stages in this way,the resins which are formed on the side wall sections and on the metalreflective film can be made to have different qualities and formulae,and it is thus possible to combine them such that each exhibits suitableperformance. Furthermore, formation is easier when the resin is paintedon than integrated formation, and the shielding ability of the resin canbe secured.

FIGS. 27A through 27D-are sectional views showing the fourteenthembodiment of the scintillator panel according to the present inventionand an example of modification thereof. In these embodiments, the orderof lamination of the first protective organic film 142 and the secondprotective organic film 143 is made to be different from that of thethirteenth embodiment. That is, in these embodiments, the secondprotective organic film 143 covers the peripheral edges of the firstprotective organic film 142.

Here, as illustrated in FIG. 27A, it is sufficient for the secondprotective organic film 143 to extend to the edges of the rear surfaceof the substrate 10, but it is preferable that this film extend to therear surface of the substrate 10, as shown in FIG. 27B. On the otherhand, it is acceptable for the first protective organic film 142 toextend to the side walls of the substrate 10, as shown in FIG. 27C. Itis also acceptable for the second protective organic film 143 to extendto the peripheral edges of the metal reflective film 12, as shown inFIG. 27D.

Next, the making method for this scintillator panel if will beexplained. This method is the same as the making process of thescintillator panel 1 b shown in FIGS. 19A and B up to the manufacture ofthe metal reflective film 12. Thereafter, polyimide resin is paintedover the metal reflective film 12 and the surfaces of the substrate 10on the periphery of the metal reflective film 12, and then caused toharden, thus forming the first protective organic film 142 in planarform, covering the metal reflective film 12 (see FIG. 28A).

Subsequently, polyimide resin is painted onto the side walls of thesubstrate 10 and the proximal substrate surfaces up to the peripheraledges of the first protective organic film 142, and then caused toharden, thus forming the second protective organic film 143 in a frameshape (see FIG. 28B). The second protective organic film 143 may beformed by affixing resin molded into the form of a tape or film ratherthan by painting on the resin.

Next, similarly to the process in FIG. 19D, a large number of Tl-dopedCsI needle crystals are grown by deposition in a predetermined area onthe surface of the protective organic film 14 d (actually the firstprotective organic film 142) over the metal reflective film 12, thusforming the scintillator 16 (see FIG. 28C). To complete the scintillatorpanel 1 d shown in FIG. 27A, the scintillator 16 is covered with amoisture-proof organic film 18 made of polyparaxylylene.

In this embodiment also, the protective organic film 14 d is formed intwo stages, and thus the same effects as those of the thirteenthembodiment may be obtained.

FIG. 29 is a sectional constitutional diagram showing the fifteenthembodiment of the scintillator panel according to the present invention.In this scintillator panel 1 g, the metal reflective film 12 is formedon one surface of the radiolucent substrate 10 (made of a material inwhich the main component is glass, amorphous carbon, or another carbon).This metal reflective film 12 is comprised of a material containing oneof Al, Ag, Cr, Cu, Ni, Ti, Mg, or Rh. A first protective organic film 14is formed so as to envelop the substrate 10 from above the metalreflective film 12. This first protective organic film 14 is made, forexample, from polyparaxylylene. A scintillator 16 which converts intovisible light incident radiation that has passed through the substrate10 is formed on the portion of the surface thereof on which the metalreflective film 12 and the first protective organic film 14 arelaminated. A Tl-doped CsI, for example, is used as this scintillator 16.The CsI has a configuration in which a large number of needle crystalsstand grouped together. A second protective organic film 19 is formed inthe shape of a picture frame covering an area extending from theperipheral edges of the top surface of the scintillator 16 to the edgesof the rear surface of the substrate 10. This protective organic film 19is made of polyimide, for example. This second protective organic film19 adheres to the side walls of the scintillator 16 and also adheres tothe first protective organic film 10, thereby covering the surfaces ofthe substrate 10 on the periphery of the scintillator 16 and the sidewalls of the substrate 10 from over the first protective organic film14. The entire scintillator panel 1 g is substantially covered with apolyparaxylylene moisture-proof organic film 18.

Next, the making method of this scintillator panel 1 g will beexplained. First, a rectangular or circular substrate 10 (thickness: 1mm) is prepared (see FIG. 31A), and a metal reflective film 12 is formedon a surface thereof at a thickness of 150 nm by vacuum deposition (seeFIG. 31B).

Next, a protective organic film 14 made of polyparaxylylene is formed onthe metal reflective film 12 by CVD. In other words, the substrate 10with the metal reflective film 12 deposited thereon is placed in a CVDdevice, wherein a moisture-proof film 12 is formed over the entiresurface of the substrate 10 at a thickness of 10 μm. In so doing, apolyparaxylylene protective organic film 14 is formed, covering themetal reflective film 12 and also substantially covering the entiresubstrate 10, from the periphery of the substrate reflective film 11 tothe side walls thereof, and furthermore to the rear surface thereof (seeFIG. 31C). The making method for this organic film is described indetail in International Publication No. WO99/66351.

Next, a large number of Tl-doped CsI needle crystals are grown bydeposition in a predetermined area on the surface of the protectiveorganic film 14 over the metal reflective film 12, thus forming thescintillator 16 at a thickness of 250 μm (see FIG. 31D)

Subsequently, polyimide tape is wound and fixed around the partextending from the peripheral edges of the top surface of thescintillator 16, over the exposed wall surfaces of the scintillator 16and the exposed first protective organic film 14 on the periphery of thescintillator 16, up to the peripheral edges of the rear surface of thesubstrate 12, thus forming the second protective organic film 19 (seeFIG. 31E). Polyimide resin which has been molded into sheet form may beused as this tape, as may tape to which an adhesive has been applied,such as Kapton Tape by E. I. du Pont de Nemours and Company.

The CsI that forms the scintillator 16 has high hygroscopicity, and ifleft exposed, absorbs vapor in the air and deliquesces. In order toprevent this, the scintillator 16 is covered with a polyparaxylylenemoisture-proof organic film 18 (thickness: 10 μm), thus completing thescintillator panel 1 g as shown in FIG. 29. This moisture-proof organicfilm 18 may be formed by the same making process as the protectiveorganic film 14.

As is shown in FIG. 29, this scintillator panel 1 g is disposed suchthat the scintillator 16 faces the opposite side to the radiationentrance side, and the image-sensing element, television camera and soon are disposed and used on the scintillator 16 side. It goes withoutsaying that an optical system which is not illustrated may be used tolead output images from the scintillator 16 to the image-sensingelement, television camera or the like.

Radiation enters the scintillator panel 1 g from the direction of thearrow A, passes through the moisture-resistant protective film 14, thefirst protective organic film 14, the substrate 10, the metal reflectivefilm 12, and the first protective organic film 14 in succession, andreaches the scintillator 16. Here, the radiation is absorbed by thescintillator 16 and emitted as visible light. Of the emitted visiblelight, the light directed toward the substrate 10 side passes throughthe transparent protective organic film 14, and is thereafter reflectedby the metal reflective film 12 to return to the scintillator 16 side.As a result, the bulk of the light emitted from the scintillator 16passes through the moisture-resistant protective film 14 and is radiatedin the direction of arrow B. In the image-sensing element or televisioncamera (not shown), this optical image is captured, and thus an imagesignal corresponding to a radiographic image can be obtained.

The side walls of the scintillator panel 1 g of this embodiment arefortified by the second protective organic film 19, and hence themechanical strength of this part can be improved. These side wall partsare not positioned on the light path of the radiation and the visiblelight which is converted by the scintillator 16, and it is thereforepossible to increase the thickness of the side wall parts so as toobtain the necessary strength without influencing the radiationcharacteristic and optical characteristic of the scintillator 16.Conversely, the substrate 10 part can be made with a large surface areawhile remaining thin, thereby enabling a combination of a large-sizedscreen with high resolution and a high S/N ratio.

In order to activate the scintillator 16, annealing processing, in whichthe scintillator 16 is heated following formation, is sometimesperformed. In the scintillator panel 1 according to the presentinvention, this annealing processing is possible either before or afterthe formation process of the second protective organic film 19 (see FIG.31E).

When annealing processing is performed before the second protectiveorganic film 19 is formed, there is a possibility that damage such aspin holes will occur in the exposed part of the first protective organicfilm 14 due to the heat during annealing processing. However, byblocking these damaged parts, scintillator components or moisture areprevented from penetrating into the metal reflective film 12 during usefollowing manufacture.

When annealing processing is performed after the second protectiveorganic film 19 is formed, the second protective organic film functionsas a moisture-resistant protective film to prevent excess heat frombeing applied to the first protective organic film 11 during annealingprocessing, and hence damage to the first protective organic film 14 maybe suppressed. In this case, the second protective organic film 19requires better heat resistance than the first protective organic film,and polyimide resin is suitable since it has good heat resistance.

As noted above, the second protective organic film 19 is not positionedon the light path of the output light from the scintillator 16.Consequently, it is preferable that the second protective organic film19 be opaque with respect to the light generated by the scintillator 16(preferably with 50% transmissivity or less, and more preferably 10%transmissivity or less). When the second protective organic film 19 ismade opaque in this manner, ambient light passes through the secondprotective organic film 19 to enter the scintillator 16, where thisambient light is refracted and reflected, thereby preventing itsintrusion into the output image as noise. As a result, an output imagewith a good S/N ratio can be obtained.

The second protective organic film 19 does not necessarily have to coverthe area extending from the peripheral edges of the rear surface of thesubstrate 10 to the peripheral edges of the top surface of thescintillator 16, and it is sufficient if the film 19 covers the sidewalls of the substrate 10 and scintillator 16 and the first protectiveorganic film 14 therebetween, as is shown in FIG. 30. In so doing, theoptical output surface may be made larger.

FIG. 32 is a sectional view showing the sixteenth embodiment of thescintillator panel according to the present invention. This scintillatorpanel 1 h differs from that of the fifteenth embodiment in that apolyimide film is used as the protective organic film 14 h, and thisfilm is not formed up to the rear surface of the substrate 10.

This polyimide protective organic film 14 h may be manufacturedfollowing the making process of the metal reflective film 12 shown inFIG. 31B by applying polyimide resin over the metal reflective film 12down to the side walls of the substrate 10 at a constant thickness (10μm) and causing this resin to harden.

When the first protective organic film 14 h is formed withheat-resistant polyimide resin, it is difficult to envelop the entiresubstrate 10 therein, as with the polyparaxylylene first protectiveorganic film 14 in the first embodiment. However, in the annealingprocessing step to activate the scintillator 16, damage to theprotective organic film 14 h can be suppressed.

FIG. 33 is a sectional view showing the seventeenth embodiment of thescintillator panel according to the present invention. The scintillatorpanel 1 i of this embodiment differs from the scintillator panel 1 ofthe second embodiment in that the second protective organic film 19 isformed on the outside of the moisture-resistant protective film 18. Inother words, the moisture-resistant protective film 18 in thisscintillator panel 1 b is formed so as to substantially cover the entirepanel from the top surface to the side walls of the scintillator 16, thesurfaces of the first protective organic film 14 on the periphery of thescintillator 16, and from the side walls to the rear surface of thesubstrate 10. Further, a second protective organic film 19 is configuredin the form of a picture frame, covering the side walls of thescintillator panel 1 i, that is, covering the moisture-resistantprotective film 18 from the side walls of the scintillator 16 to theside walls of the substrate 10.

Here, it is sufficient if the second protective organic film 19 extendsto at least the edges of the side walls of the substrate 10 and thescintillator 16, but it is also acceptable for the film to extend to therear surface of the substrate 10 or the top surface of the scintillator16.

Next, the method of making this scintillator panel 1 i will beexplained. This method is identical to the making process for thescintillator panel 1 g illustrated in FIGS. 31A and 31B up to themanufacture of the metal reflective film 12 (FIGS. 34A and 34B).Thereafter, polyimide resin is painted onto the metal reflective film 12and the surfaces of the substrate 10 around the periphery of the metalreflective film 12, and then caused to harden, thereby forming the firstprotective organic film 14 in planar form, covering the metal reflectivefilm 12 (see FIG. 34C).

Next, similarly to the process in FIG. 31D, a large number of Tl-dopedCsI needle crystals are grown by deposition in a predetermined area onthe surface of the first protective organic film 14 on the metalreflective film 12, and thus the scintillator 16 is formed (see FIG.34D). Then, the scintillator 16 is covered by a polyparaxylylenemoisture-proof organic film 18 (see FIG. 34E). Then, polyimide resin ispainted over the moisture-proof organic film 18 onto the side walls ofthe substrate 10 and the scintillator 16 and all of the intermediateparts therebetween, and caused to harden, thereby forming theframe-shaped second protective organic film 19 and completing thescintillator panel 1 i as shown in FIG. 33. Similarly to the fourteenthembodiment, the second protective organic film 19 maybe formed byaffixing resin molded into the form of a tape or film rather than bypainting on the resin.

In this embodiment, since the scintillator panel 1 j, including themoisture-proof organic film 18, is covered by the protective organicfilm 19, and is thus supported at the side wall parts, there is nodanger of damage to the moisture-proof organic film 18, and peelingcaused by damage to the moisture-proof organic film 18 can besuppressed.

Next, one example of supporting and fixing the scintillator panelaccording to the present invention will be explained. FIGS. 35 through38 are views showing an eighteenth embodiment of the scintillator panelaccording to the present invention. FIG. 35 is a front view of thisscintillator panel 1 j seen from the scintillator 16 side, FIG. 36 is aback view seen from the substrate 10 side, and FIGS. 37 and 38 aresectional views on the XXXVII-XXXVII line and the XXXVIII-XXXVIII lineof FIG. 35 respectively.

This scintillator panel 1 j has the same basic structure as thescintillator panel 1 i of the sixteenth embodiment shown in FIG. 33, butdiffers therefrom in that the substrate surface and the width of therear surface part of the second protective organic film 19 j arecomparatively larger.

In the scintillator panel 1 j, the laminated structure of the metalreflective film 12, the first protective organic film 14, and thescintillator 16 is formed in the central part of the substrate 10,providing space on the periphery of the scintillator 16. In the fourcorners of the substrate 10 (within this area of space on theperiphery), through holes 190 are provided through the substrate 10.These through holes 190 are provided in the substrate 10 in advance,prior to the formation of the scintillator 16.

The scintillator panel 1 j can be fixed by inserting and fixing bolts,screws or the like into these through holes 190. Since the secondprotective organic film 19 j protects the subjacent substrate 10 andmoisture-resistant organic film 18, damage thereto during fixing can besuppressed. If the moisture-resistant film 18 were to lie exposed, themoisture-resistant film 18 would be damaged when screws and the likewere inserted and tightened, allowing moisture to enter the interiorthrough [the damaged area]. However, since the moisture-resistantorganic film 18 is protected by the second protective organic film 19 c,damage is unlikely to occur to the moisture-resistant organic film evenwhen screws and the like are inserted and tightened. In FIG. 37, thescintillator 16 is depicted in a protruding state; however, the secondprotective organic film 19 j may be formed thicker than the scintillator16 in order to strengthen its protecting function.

It is acceptable to form the second protective organic film 19 j so asto cover the entire rear surface of the scintillator panel 1 j. However,in order to obtain a clearer output image, it is preferable not to formthe second protective organic film 19 j on the radiographic image inputpart.

In the above-described embodiments, CsI (Tl) is used as the scintillator16. However, the present invention is not limited to this, and CsI (Na),NaI (Tl), LiI (Eu), KI (Tl), or the like may be used.

In the above-described embodiments, the entire surfaces of thescintillator 16 and substrate (the surface with the scintillator formedand a surface on the opposite side, i.e., the radiation incidentsurface) are covered with the polyparaxylylene film 18, thereby makingthe scintillator completely resistant against water vapor. When thescintillator 16 and at least part of the surface of the substrate arecovered with the polyparaxylylene film 18, as shown in FIG. 13, thewater-vapor resistance of the scintillator can be made higher than in acase wherein only the scintillator is covered.

Polyparaxylylene in the above-described embodiments includes, inaddition to polyparaxylylene, polymonochloroparaxylylene,polydichloroparaxylylene, polytetrachloroparaxylylene,polyfluoroparaxylylene, polydimethylparaxylylene,polydiethylparaxylylene, and the like.

According to the scintillator panel of the present invention, any changein properties of the reflective metal thin film based on water containedin the scintillator in a small amount can be prevented, and the functionof the reflective metal thin film as a reflecting film can be preventedfrom degrading. Hence, an increased optical output of the scintillatorpanel can be maintained. When a glass substrate is used, even ascintillator panel having a large area can keep its performance high.

In addition, according to the radiation image sensor of the presentinvention, since the scintillator panel can maintain an increasedoptical output, the output of the radiation image sensor can bemaintained. When a glass substrate is used, even a radiation imagesensor having a large area can keep its performance high.

From the invention thus described, it will be obvious that the inventionmay be varied in many ways. Such variations are not to be regarded as adeparture from the spirit and scope of the invention, and all suchmodifications as would be obvious to one skilled in the art are intendedfor inclusion within the scope of the following claims.

1-66. (canceled)
 67. A panel for detection of radiation ray, comprising:a support substrate on which a plurality of columnar crystal made ofalkali-halide system material are formed as a large number of needlecrystals; said support substrate comprising; a substrate; and a firstorganic film substantially enveloping said substrate; and said panelfurther comprising a second organic film substantially enveloping saidcolumnar crystal formed on the support substrate and the supportsubstrate.
 68. The panel according to claim 67, wherein substratecomprises carbon or aluminum as a main component.
 69. The panelaccording to claim 67, wherein the material of the first organic film isthe same as that of the second organic film.
 70. The panel according toclaim 67, wherein either one of the first and second organic films ismade of polyparaxylylene system material.
 71. The panel according toclaim 67, further comprising a reflective film made of metal between thefirst organic film and the plural columnar crystal.
 72. The panelaccording to claim 70, wherein the polyparaxylylene system materialcomprises polyparaxypolymonochloroparaxylylene,polydichloroparaxylylene, polytetrachloroparaxylylene,polyfluoroparaxylylene, polydimethylparaxylylene, andpolydiethylparaxylylene.